Colloquium paper: resistance, resilience, and redundancy in microbial communities

Abstract

Although it is generally accepted that plant community composition is key for predicting rates of ecosystem processes in the face of global change, microbial community composition is often ignored in ecosystem modeling. To address this issue, we review recent experiments and assess whether microbial community composition is resistant, resilient, or functionally redundant in response to four different disturbances. We find that the composition of most microbial groups is sensitive and not immediately resilient to disturbance, regardless of taxonomic breadth of the group or the type of disturbance. Other studies demonstrate that changes in composition are often associated with changes in ecosystem process rates. Thus, changes in microbial communities due to disturbance may directly affect ecosystem processes. Based on these relationships, we propose a simple framework to incorporate microbial community composition into ecosystem process models. We conclude that this effort would benefit from more empirical data on the links among microbial phylogeny, physiological traits, and disturbance responses. These relationships will determine how readily microbial community composition can be used to predict the responses of ecosystem processes to global change.

Fig. 1.

A schematic of how disturbance can change microbial composition and thereby affect ecosystem processes versus when disturbance would not have this effect (when the microbial community is resistant, resilient, or functionally redundant).

Fig. 2.

A physiological response curve for a microbial taxon. The curve illustrates the rate at which the taxon contributes to an ecosystem process as a function of disturbance intensity. For simplicity, this function is assumed to be linear, although other forms are likely for microbial taxa. The slope m of the line indicates how quickly the physiological rate changes with I, and r₀ is the physiological rate in the absence of disturbance.

Fig. 3.

A stylized illustration comparing the phylogenetic relationship of physiological traits versus process responses to disturbance among taxa. Different rates of the physiological traits are represented by differently sized circles (see text for further explanation). In A physiological trait values are correlated with phylogenetic similarity, whereas in B physiological trait values are randomly distributed among taxa. Three different disturbances (A, B, and C) produce process responses from the taxa that are also either phylogenetically related (disturbances A and B) or randomly distributed among taxa (disturbance C).